Building facades of natural stone slabs which are quarried and shaped by stone masons are complicated to attach to building structures. In particular, they require expensive fastening and suspending structures to enable them to be supported on the building structure and complex systems for mounting them so that gaps between adjacent slabs are maintained with precision as is required on esthetic grounds.
It has been proposed heretofore to face such structures with large-format prefabricated plates of reinforced concrete which can be provided in a variety of configurations.
Such concrete slabs can be fabricated in a simple manner and the technique of fastening them to the building structure, e.g. on existing walls or building frameworks, is well developed. The suspension and attachment elements may be embedded in the concrete upon casting.
It is also known to provide so-called composite elements utilizing steel-reinforced steel slabs which themselves ar provided with facings, e.g. of ceramic plates. In earlier systems, the connection of the facing plate to the reinforced concrete slab has not been satisfactory since the connection was neither completely reliable nor capable of withstanding all of the stresses to which the slabs can be subject. Specifically, it could not always be ensured that the fixing member would not come loose from the supporting concrete slab.
Because of the poor attachment of the fixing layer and the inability to insure that the attachment would withstand the thermal, weather, wind and other stresses to which the attachment is subject, composite elements of this latter type have not been used as widely as might otherwise be the case.